Template:Jeremejevite

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Jeremejevite
Chemical composition Al6B5O15(F,OH)3
Crystal system Hexagonal or Orthorhombic*
Habit Prismatic
Cleavage None
Fracture Concoidal
Hardness 7
Optic nature Uniaxial (-) or biaxial*
Refractive index nω=1.653 nε=1.640
Birefringence δ = 0.013
Dispersion 0.0130
Specific gravity 3.27-3.31
(Webster,1994,p.898)
Lustre Vitreous
Pleochroism Faint to Strong